Video security systems have been traditionally used to help protect people, property, and reduce crime for homeowners and businesses alike and have become an increasingly cost-effective tool to reduce risk. Modern systems with video analytics capabilities provide the ability to detect and track individuals and objects within monitored scenes. These systems can provide both live monitoring of individuals, and forensic analysis of saved security video data to spot trends and search for specific behaviors of interest. Of increasing interest is the monitoring of point of sale (“POS”) areas to track customer movement near POS terminals. This can be used, for example, to detect potentially suspicious transactions.
Video security cameras capture images of three-dimensional scenes and represent the images as frames of image data that typically represent two-dimensional arrays of pixel data. Sometimes, the image data are sent as video. Data stored in association with the image data are referred to as metadata. Components in modern video security systems use the generated metadata for analysis purposes.
Some existing systems that track customer movements near POS terminals rely on video cameras positioned directly overhead of the POS terminals, often referred to as “look-down” cameras. To infer customer movement near POS terminals, these systems compare video data taken from overhead cameras to simple relational cues that are notionally superimposed upon the video data. An example of a relational cue is a horizontal line drawn upon the video data near the POS terminal. A determination of whether customers are near a POS terminal involves an analysis of customers who cross this line or come within a certain distance to the line.